N,N-dimethyl-3-(trimethoxysilyl)propylamine

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

February - April 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EU Method B.40 BIS (In Vitro Skin Corrosion: In vitro Skin Corrosion: Human Skin Model Test, May 30, 2008)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: ECVAM INVITTOX Protocol No 118: "EpiSkin™ Skin Corrosivity Test"; December 2011

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

N,N-dimethyl-3-(trimethoxysilyl)propylamine

EC Number:

219-786-3

EC Name:

N,N-dimethyl-3-(trimethoxysilyl)propylamine

Cas Number:

2530-86-1

Molecular formula:

C8H21NO3Si

IUPAC Name:

dimethyl[3-(trimethoxysilyl)propyl]amine

Test material form:

liquid

Details on test material:

- Name (as cited in the report): SAT 170001
- Chemical Name: N,N-dimethyl-3-(trimethoxysilyl)propylamine
- CAS No.: 2530-86-1
- Batch No.: 186020160504
- Aggregate State at RT: liquid
- Colour: colourless
- Storage Conditions: room temperature
- Expiry Date: 30.08.2017

In vitro test system

Test system:

human skin model

Remarks:

EpiSkin-SM (TM)

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

foreskin from a single donor

Source strain:

not specified

Justification for test system used:

This test uses the EPISKIN-SM™ reconstructed human epidermis model (SkinEthic) which consists of normal human epidermal keratinocytes (NHEK) and therefore represents in vitro the target organ of the species of interest and closely mimics the biochemical and physiological properties of the upper parts of the human skin, i.e. the epidermis.

Vehicle:

unchanged (no vehicle)

Details on test system:

The test was carried out with the reconstituted three-dimensional human skin model EPISKIN-SM™ (SkinEthic). This skin model consists of normal human epidermal keratinocytes (NHEK) which have been cultured to form a multilayered, highly differentiated model of the human epidermis. The NHEK are cultured on chemically modified, collagen-coated cell culture inserts. A highly differentiated and stratified epidermis model is obtained after 13-day culture period comprising the main basal, supra basal, spinous and granular layers and a functional stratum comeum.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

The test item was applied undiluted. 50 ± 3 μL (131.6 μL/cm2) of the test item was dispensed directly atop the EPISKIN-SM™ tissue using a positive displacement pipette. The test item was spread to match size of the tissue.

Duration of treatment / exposure:

30 min, 60 min, 4 h

Duration of post-treatment incubation (if applicable):

3 h MTT incubation

Number of replicates:

duplicate cultures per test

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Remarks:

NSMTT-corrected

Run / experiment:

Test item / 3 min

Value:

99

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Remarks:

NSMTT-corrected

Run / experiment:

Test item / 60 min

Value:

91

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Results 3

Irritation / corrosion parameter:

% tissue viability

Remarks:

NSMTT-corrected

Run / experiment:

Test item / 4 h

Value:

78

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

PRE-EXPERIMENTS

The mixture of 50 μL test item per 2 ml MTT medium showed reduction of MTT as compared to the solvent. The mixture turned blue/purple.

For quantitative correction of results, the part of absorption due to the non-specific reduction of MTT (NSMTT) was determined by using killed tissues. Therefore, two tissues per treatment period were treated with the test item (KT) and with 0.9% NaCI; KU, respectively. NSMTT was calculated relative to the negative control of living tissues (NK) per treatment period according to the following formula:

NSMTT = [(OD(KT) - OD(KU)) / OD(NK)] * 100

NSMTT was <= 50% relative to the negative control of living epidermis. In the 3 min experiment NSMTT was 1.0%, in the 60 min experiment 2.3%, in the 4 h experiment 12.5%. The true MTT metabolic conversion [TOD(TT)] of the test item treated living tissues (TM) was corrected for each treatment period according to the following formula:

TOD(TT) = OD(TM) - [OD(KT) - OD(KU)]

The mixtures of 10 μL test item per 90 μL Aqua. dest. and per 90 μL isopropanol showed no colouring as compared to the solvent. Therefore NSCnving equaled 0%.

TEST RESULTS

3 MIN EXPERIMENT	Negative Control	Test Item	Positive Control
total mean OD570 (mean 2 replicates)	0.850	0.853	n.a.
mean rel. tissue viability [%]	100	100	n.a.
mean inter tissue viability diff. [%]	5.7	8.1	n.a.

60 MIN EXPERIMENT	Negative Control	Test Item	Positive Control
total mean OD570 (mean 2 replicates)	0.821	0.748	n.a.
mean rel. tissue viability [%]	100	93	n.a.
mean inter tissue viability diff. [%]	0.2	5.0	n.a.

4 H EXPERIMENT	Negative Control	Test Item	Positive Control
total mean OD570 (mean 2 replicates)	0.687	0.623	0.035
mean rel. tissue viability [%]	100	91	5
mean inter tissue viability diff. [%]	11.4	9.4	1.2

The test item showed non-specific MTT-reducing potential. Therefore, additional killed tissue controls were treated with the test item to determine the non-specific reduction of MTT (NSMTT) and the results were corrected to the true MTT metabolic conversion (TOD(TT)). The test item showed no water-colouring potential.

The test item showed no corrosive effects. The mean relative tissue viability (% negative control) was >= 35% (78%, NSMTT-corrected) after 4 h treatment.

Relative mean tissue viability was reduced to 91 % after 60 min treatment and to 99% after 3 min treatment (NSMTT-corrected values).

The controls confirmed the validity of the study. The mean OD570 of the two negative control tissues was between 0.6 and 1.5 for each exposure period. The mean relative tissue viability (% negative control) of the positive control was <= 20% (5%) after 4 h treatment. The maximum inter tissue viability difference of replicate tissues of all dose groups was <= 30% (0.2% - 11.4%).

Applicant's summary and conclusion

Interpretation of results:

other: not corrosive

Remarks:

Criteria used for interpretation of results: other: OECD 431

Conclusions:

In this study under the given conditions the test item showed no corrosive effects. The relative mean tissue viability after 4 h treatment was not decreased to less than 35% of the corresponding negative control tissues. The test item is therefore classified as "non-corrosive".

Executive summary:

In the present study the skin corrosivity potential of the test item was analysed. Since corrosive chemicals are cytotoxic after topical short-time exposure to the EPISKIN-SM ™, a reconstituted

three-dimensional human epidermis model, the cytotoxic effects of the test item were determined. Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT after a 3 min, 60 min and 4 h exposure period and compared to those of the concurrent negative controls.

The test item showed non-specific MTT-reducing potential. The test item showed no water-colouring potential. The mean relative tissue viability (%negative control) was >= 35% (78%, NSMTTcorrected) after 4 h treatment. Relative mean tissue viability was reduced to 91 % after 60 min treatment and to 99% after 3 min treatment (NSMTT-corrected values).

Conclusion

In this study under the given conditions the test item showed no corrosive effects.

The relative mean tissue viability after 4 h treatment was not decreased to less than 35% of the corresponding negative control tissues.

The test item is therefore classified as "non-corrosive".